:root {
            --primary-color: #1d1d1f;
            --secondary-color: #86868b;
            --accent-color: #0071e3;
            --bg-color: #f5f5f7;
        }

        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: -apple-system, BlinkMacSystemFont, 
                'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell,
                'Open Sans', 'Helvetica Neue', sans-serif;
        }

        body {
            background-color: var(--bg-color);
            color: var(--primary-color);
            -webkit-font-smoothing: antialiased;
            overflow-x: hidden;
        }

        /* 导航容器 */
        .nav-container {
            position: fixed;
            top: 0;
            width: 100%;
            background: rgba(255, 255, 255, 0.8);
            backdrop-filter: blur(20px);
            z-index: 1000;
            border-bottom: 1px solid rgba(0, 0, 0, 0.1);
        	
        }
        
        /* 导航主体 */
        .nav-wrapper {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }
        
        /* 主导航栏 */
        .main-nav {
            display: flex;
            justify-content: space-between;
            align-items: center;
            height: 60px;
        }
        
        .logo {
            font-size: 24px;
            font-weight: 600;
            color: #000;
            text-decoration: none;
        }
        
        /* 导航菜单 */
        .nav-menu {
            display: flex;
            list-style: none;
            height: 100%;
        }
        
        .nav-item {
            position: relative;
            padding: 0 20px;
            height: 100%;
            display: flex;
            align-items: center;
        }
        
        .nav-link {
            text-decoration: none;
            color: #666;
            font-size: 14px;
            transition: color 0.3s;
            position: relative;
        }
        
        .nav-link:hover {
            color: #000;
        }
        
        /* 横向下拉菜单 */
        .dropdown-horizontal {
            position: absolute;
            top: 100%;
            left: 0;
            width: 200vw;
            margin-left: -100vw;
            left: 50%;
            background: rgba(255,255,255,0.92);
            backdrop-filter: blur(30px);
            display: none;
            padding: 40px 0;
            box-shadow: 0 20px 30px rgba(0,0,0,0.1);
            border-top: 1px solid rgba(0,0,0,0.1);
        }
        
        .dropdown-content {
            max-width: 1200px;
            margin: 0 auto;
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: 40px;
            padding: 0 20px;
        }
        
        .menu-section h3 {
            font-size: 12px;
            color: #666;
            margin-bottom: 15px;
            font-weight: 500;
            text-transform: uppercase;
        }
        
        .menu-section ul {
            list-style: none;
        }
        
        .menu-section li {
            margin-bottom: 12px;
        }
        
        .menu-section a {
            color: #000;
            text-decoration: none;
            font-size: 16px;
            transition: opacity 0.3s;
        }
        
        .menu-section a:hover {
            opacity: 0.7;
        }
        
        /* 交互效果 */
        .nav-item:hover .dropdown-horizontal {
            display: block;
            animation: menuSlide 0.3s cubic-bezier(0.23, 1, 0.32, 1);
        }
        
        @keyframes menuSlide {
            from {
                opacity: 0;
                transform: translateY(-10px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        /* 主内容 */
        .hero-section {
            min-height: 100vh;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            text-align: center;
            padding: 120px 20px 80px;
            opacity: 0;
            transform: translateY(80px);
            transition: all 1s cubic-bezier(0.4, 0, 0.2, 1);
        }

        .hero-section.active {
            opacity: 1;
            transform: translateY(0);
        }

        .institute-logo {
            width: 600px;
            margin-bottom: 40px;
			border-radius: 10%;
        }

        h1 {
            font-size: 64px;
            font-weight: 600;
            margin-bottom: 24px;
            line-height: 1.05;
        }

        .hero-text {
            font-size: 24px;
            color: var(--secondary-color);
            max-width: 800px;
            margin: 0 auto 40px;
            line-height: 1.4;
        }

        /* 研究院介绍模块 */
        .about-section {
            padding: 120px 20px;
            max-width: 980px;
            margin: 0 auto;
            opacity: 0;
            transform: translateY(80px);
            transition: all 1s cubic-bezier(0.4, 0, 0.2, 1);
        }

        .about-section.active {
            opacity: 1;
            transform: translateY(0);
        }

        .section-title {
            font-size: 40px;
            font-weight: 600;
            margin-bottom: 40px;
            text-align: center;
        }

        .about-grid {
            display: grid;
            grid-template-columns: repeat(1, 1fr);
            /* gap: 60px; */
            align-items: center;
        }

        .about-image {
            border-radius: 18px;
            overflow: hidden;
            box-shadow: 0 25px 50px -12px rgba(0,0,0,0.1);
        }

        .about-text {
            font-size: 18px;
            color: var(--secondary-color);
            line-height: 1.5;
            text-align: justify;
            max-width: 920px;
            margin: 0 auto;
        }
        .about-text p {
            text-indent: 2em;
            text-align: justify;
            line-height: 1.5;
            margin-bottom: 1.1em;
        }

        .about-text p:last-child {
            margin-bottom: 0;
        }

        .highlight {
            color: var(--primary-color);
            font-weight: 500;
        }

        /* 研究方向模块 */
        .research-section {
            padding: 120px 20px;
            background: white;
            margin: 120px 0;
            opacity: 0;
            transform: translateY(80px);
            transition: all 1s cubic-bezier(0.4, 0, 0.2, 1);
        }

        .research-section.active {
            opacity: 1;
            transform: translateY(0);
        }

        .research-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 40px;
            max-width: 980px;
            margin: 0 auto;
        }

        .research-card {
            text-align: center;
            padding: 40px;
            background: var(--bg-color);
            border-radius: 18px;
            transition: all 0.3s;
        }

        .research-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 25px 50px -12px rgba(0,0,0,0.1);
        }

        .research-icon {
            width: 60px;
            margin-bottom: 24px;
        }

        .research-title {
            font-size: 21px;
            font-weight: 600;
            margin-bottom: 16px;
        }

        .research-description {
            font-size: 15px;
            color: var(--secondary-color);
            line-height: 1.4;
        }

        /* 响应式设计 */
        @media (max-width: 768px) {
            h1 {
                font-size: 48px;
            }

            .about-grid,
            .research-grid {
                grid-template-columns: 1fr;
            }

            .hero-text {
                font-size: 20px;
            }

            /* 新增：移动端图片尺寸小一点 */
            .institute-logo {
                width: 90vw;
                max-width: 320px;
                margin-bottom: 24px;
            }
        }
		
		/* 页脚 */
		footer {
		    background: #1d1d1f;
		    color: #f5f5f7;
		    padding: 40px 20px;
		    text-align: center;
			position: relative;
			bottom: 0px;
		}
		
		footer a {
		    color: #f5f5f7;
		    text-decoration: none;
		    margin: 0 10px;
		}
		
		footer a:hover {
		    text-decoration: underline;
		}
        /* 移动端样式 */
        @media (min-width: 769px) {
            /* PC端时隐藏移动端导航 */
            .mobile-header,
            .mobile-menu {
                display: none !important;
            }
            
            /* PC端时显示主导航 */
            .nav-container {
                display: block;
            }
        }

        @media (max-width: 768px) {
            /* 移动端时隐藏PC导航 */
            .nav-container {
                display: none !important;
            }
            
            /* 移动端时显示移动导航 */
            .mobile-header {
                display: flex !important;
            }
        }
        @media (max-width: 600px) {
            .nav-container {
                display: none; /* 隐藏桌面导航 */
            }

            .mobile-header {
                display: flex;
                justify-content: space-between;
                align-items: center;
                padding: 10px 20px;
                background: rgba(255, 255, 255, 0.9);
                border-bottom: 1px solid rgba(0, 0, 0, 0.1);
                position: relative;
                z-index: 1001;
            }

            /* 移动端菜单按钮和菜单样式 */
        @media (max-width: 768px) {
            .main-nav, .nav-menu, .nav-login {
                display: none !important;
            }
            .mobile-header {
                display: flex;
                align-items: center;
                justify-content: space-between;
                height: 60px;
                padding: 0 16px;
                background: rgba(255,255,255,0.95);
                position: fixed;
                top: 0;
                left: 0;
                width: 104vw;
                z-index: 1200;
                border-bottom: 1px solid #eee;
            }
            .mobile-logo {
                font-size: 16px;
                font-weight: 600;
                color: #222;
                text-decoration: none;
                flex: 1;
                white-space: nowrap;
                overflow: hidden;
                text-overflow: ellipsis;
            }
            .mobile-menu-btn {
                background: none;
                border: none;
                font-size: 28px;
                color: #222;
                cursor: pointer;
                padding: 8px;
                margin-left: 90px;
            }
            .mobile-menu {
                display: none;
                position: fixed;
                top: 0;
                left: 0;
                width: 100vw;
                height: 100vh;
                background: #222;
                color: #fff;
                z-index: 2000;
                flex-direction: column;
                padding-top: 60px;
                transition: transform 0.3s cubic-bezier(.4,0,.2,1);
                overflow-y: auto; /* 允许菜单内容滚动 */
                -webkit-overflow-scrolling: touch; /* iOS 惯性滚动 */
            }
            .mobile-menu.active {
                display: flex;
            }
            body.mobile-menu-open {
                overflow: hidden;
                position: fixed;
                width: 100vw;
            }
            .mobile-menu-close {
                position: absolute;
                top: 16px;
                right: 20px;
                background: none;
                border: none;
                color: #fff;
                font-size: 28px;
                cursor: pointer;
                z-index: 2100;
            }
            .mobile-menu-list {
                list-style: none;
                padding: 0;
                margin: 0;
                width: 100%;
            }
            .mobile-menu-list li {
                border-bottom: 1px solid rgba(255,255,255,0.08);
            }
            .mobile-menu-link {
                display: block;
                color: #fff;
                text-decoration: none;
                font-size: 18px;
                padding: 18px 28px;
                width: 100%;
                transition: background 0.2s;
            }
            .mobile-menu-link:hover {
                background: rgba(255,255,255,0.08);
            }
            .mobile-menu-dropdown {
                background: #222;
                padding-left: 32px;
            }
            .mobile-menu-dropdown a {
                color: #fff;
                font-size: 16px;
                display: block;
                padding: 12px 0;
                text-decoration: none;
            }
            .mobile-menu-dropdown a:hover {
                text-decoration: underline;
            }
            body.mobile-menu-open {
                overflow: hidden;
            }
            .carousel-container {
                margin-top: 60px !important;
            }
            .carousel-caption {
                position: absolute;
                left: 0;
                right: 0;
                bottom: 0;
                width: 100%;
                max-width: 100%;
                padding: 0.7rem 0.7rem 0.9rem 0.7rem;
                background: rgba(0,0,0,0.32);
                text-align: left;
                color: #fff;
                animation: fadeIn 1.5s ease-in-out;
            }
            .carousel-caption h2 {
                font-size: 1.15rem;
                margin-bottom: 0.5rem;
                font-weight: 700;
                color: #fff;
                text-shadow: 0 2px 6px rgba(0,0,0,0.25);
                line-height: 1.3;
            }
            .carousel-caption p {
                font-size: 0.92rem;
                margin-bottom: 0.7rem;
                line-height: 1.5;
                color: #fff;
                text-shadow: 0 1px 3px rgba(0,0,0,0.18);
            }
            .read-more {
                padding: 7px 14px;
                font-size: 0.92rem;
            }
        }
        .mobile-logo-en {
            font-size: 8px !important;
            color: #444;
            margin-top: 2px;
            letter-spacing: 1px;
            font-weight: 400;
            display: block;
            white-space: nowrap !important;
            overflow: hidden !important;
            text-overflow: ellipsis !important;
            max-width: 100vw !important;
            line-height: 1;
            word-break: keep-all !important;
            text-align: left;
        }